board_status: Point to documentation in header

This adds a pointer to the README and to the wiki in the header of
board_status.sh.

Change-Id: I5877a3bf3544f175ac74a5e5a8e1ef1cab366ab8
Signed-off-by: David Hendricks <david.hendricks@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/21569
Reviewed-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/board_status/board_status.sh

@@ -1,6 +1,7 @@
 #!/usr/bin/env sh
 #
 #
+# See README and https://www.coreboot.org/Board_Status for instructions.
 
 EXIT_SUCCESS=0
 EXIT_FAILURE=1